Gas extraction device and gas extraction method for refrigerator

ABSTRACT

A gas extraction device installed in a refrigerator removes uncondensed gases that exist in the refrigerator. The gas extraction device includes a gas extraction tank used to circulate a refrigerant put in an evaporator, a circulation pipe for circulation between the gas extraction tank and the evaporator, a gas extraction pump which feeds the refrigerant in the evaporator to the gas extraction tank, a shutoff valve configured to shut off a flow of the refrigerant from the gas extraction tank to the evaporator, a gas extractor which extracts the uncondensed gas in the refrigerator into the gas extraction tank, and an auxiliary tank which receives an inflow of the refrigerant filling up the gas extraction tank, and overflowing therefrom.

FIELD OF THE INVENTION

The present invention relates to a gas extraction device and a gasextraction method for removing uncondensed gases that exist in arefrigerator.

BACKGROUND OF THE INVENTION

In conventional refrigerators, for example, adsorption typerefrigerators and absorption type refrigerators, a refrigerant is put ina container such as a vacuumized evaporator and the condenser, and heatof evaporation generated when evaporating the refrigerant in theevaporator is used to produce cold water. The containers of theserefrigerators are injected with the refrigerant and then vacuumizedbefore shipment.

Over a long-term use of such a refrigerator, traces of air infiltratingthrough sealed sections of the container or pipes, or hydrogenassociated with internal corrosion is generated, and air and hydrogen,which are uncondensed gases, are accumulated in the container. Theseuncondensed gases that reside in the container, adversely interfere withevaporation and condensation of the refrigerant, resulting indeterioration of the refrigerator performance. To avoid that, variouslydesigned gas extraction devices have been used to draw and dischargethese uncondensed gases from the container.

The Patent document 1 discloses an absorption type refrigeratorincluding a gas extraction device which evacuates air from inside of theabsorption type refrigerator, a gas extraction tank used for storage ofthe gasses extracted by the gas extraction device, and a palladium cellfor discharging the gasses stored in the gas extraction tank out of therefrigerator. In the absorption type refrigerator, the air-impermeablepalladium cell having a hydrogen-permeability at certain temperatures isused to discharge the hydrogen out of the refrigerator.

It is disclosed in the Patent document 2 that when an absorbingsolution, such as a lithium bromide solution, is supplied from anabsorber to a regenerator by a solution pump, the uncondensed gases inthe absorber are drawn into a liquid-vapor separator to be discharged bya down-flow gas extraction device.

PRIOR ART DOCUMENT Patent Document

Patent document 1: JP-A Publication No. 2002-295929

Patent document 2: JP-A Publication No. 05-264132

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

According to the disclosures of the Patent documents 1 and 2, theuncondensed gases in vapor phase and the solution in liquid phase areseparated from each other simply by liquid-vapor separation in theliquid-vapor separator or gas extraction tank. Therefore, a deviceresistant to atmospheric pressure, such as a water ejector or a vacuumpump, is additionally necessary after the liquid-vapor separation todischarge the uncondensed gases remaining in the liquid-vapor separatoror the gas extraction tank, such as air, into atmosphere.

The present invention was accomplished to solve these conventionaltechnical problems. The present invention provides a gas extractiondevice and a gas extraction method for refrigerator configured toprevent uncondensed gases, such as air and hydrogen, from accumulatingin a gas extraction tank and further adapted to prevent the uncondensedgases and outside air from flowing into a refrigerator.

Means for Solving Problems

An aspect of the present invention provides a gas extraction device fora refrigerator, which is installed in the refrigerator configured toproduce cold water using heat of evaporation generated when evaporatinga refrigerant put in a vacuumized evaporator, the gas extraction devicefor removing an uncondensed gas that exists in the refrigeratorincluding:

a gas extraction tank for circulating the refrigerant in the evaporator;

a circulation pipe for circulation between the gas extraction tank andthe evaporator;

a gas extraction pump installed in the circulation pipe to feed therefrigerant in the evaporator to the gas extraction tank;

a shutoff valve installed in the circulation pipe so as to shut off aflow of the refrigerant from the gas extraction tank to the evaporator;

a gas extractor for extracting the uncondensed gas in the refrigeratorinto the gas extraction tank using the refrigerant supplied from theevaporator to the gas extraction tank; and

an auxiliary tank connected to an upper section of the gas extractiontank and receives an inflow of the refrigerant filling up the gasextraction tank, and overflowing therefrom.

Another aspect of the present invention provides a gas extraction methodfor a refrigerator using the above-configured gas extraction device forthe refrigerator, the method including:

gas extraction step of opening the shutoff valve accompanied with anoperation of the gas extraction pump, circulating the refrigerant in theevaporator to the gas extraction tank, and drawing the uncondensed gasin the refrigerator into the gas extraction tank using the gasextractor; and

discharging step of closing the shutoff valve accompanied with theoperation of the gas extraction pump, filling up the gas extraction tankwith the refrigerant put in the evaporator so as to be overflowed intothe auxiliary tank, and discharging the uncondensed gases drawn andstored in the gas extraction tank into the auxiliary tank.

Effect of the Invention

The gas extraction device for refrigerator employs the gas extractionpump and the gas extractor so that the refrigerant in the evaporator issupplied to the gas extraction tank by the gas extraction pump, and theuncondensed gases in the refrigerator are extracted into the gasextraction tank. After the uncondensed gases are extracted into the gasextraction tank, the shutoff valve is closed and the gas extraction pumpis operated. Then, the refrigerant supplied to the gas extraction tankby the gas extraction pump fills up the gas extraction tank and thenoverflows into the auxiliary tank.

Accordingly, all the uncondensed gases extracted into the gas extractiontank, such as air and hydrogen, are fully discharged into the auxiliarytank. Finally, the uncondensed gases are finally discharged from theauxiliary tank out of the refrigerator into atmosphere.

Thus, the gas extraction device prevents the uncondensed gases fromresiding in the gas extraction tank.

Therefore, it is unnecessary to additionally provide a device, such as awater ejector or a vacuum pump, to discharge the uncondensed gasesremaining in the vacuumized gas extraction tank (at an internal pressurelower than atmospheric pressure) into atmosphere. Further, the gasextraction tank filled with the refrigerant leaves no space for theuncondensed gases. This eliminates the possibility of backflow of theuncondensed gases and outside air into the refrigerator when theuncondensed gases are extracted by the gas extraction pump and the gasextractor.

The gas extraction device for refrigerator prevents the uncondensedgases, such as air and hydrogen, from remaining in the gas extractiontank and further prevents the uncondensed gases and outside air fromflowing back into the refrigerator.

The gas extraction method for refrigerator, by performing the gasextraction step and the discharging step, prevents the uncondensedgases, such as air and hydrogen, from remaining in the gas extractiontank and further prevent the uncondensed gases from flowing back intothe refrigerator.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is an illustration of a gas extraction device that performs a gasextracting operation (gas extraction step) according to an embodiment ofthe present invention.

FIG. 2 is an illustration of a gas extraction device that performs afilling operation (filling step) according to the embodiment.

FIG. 3 is an illustration of a gas extraction device according to theembodiment when operating a refrigerator.

FIG. 4 is an illustration of a refrigerator according to the embodiment,which is operated using a first adsorbing/desorbing device functioningas an adsorbing device and a second adsorbing/desorbing devicefunctioning as a desorbing device.

FIG. 5 is an illustration of a refrigerator according to the embodiment,which is operated using a first adsorbing/desorbing device functioningas the desorbing device and a second adsorbing/desorbing devicefunctioning as the adsorbing device.

FIG. 6 is a flowchart illustrating a gas extraction method forrefrigerator according to the embodiment.

FIG. 7 is an illustration of another gas extraction device according tothe embodiment.

MODES FOR CARRYING OUT THE INVENTION

Preferred mode of the gas extraction device and the gas extractionmethod for refrigerator as above will be described below.

The refrigerator may be formed as an adsorption type refrigerator inwhich refrigerant vapor is repeatedly adsorbed to and desorbed from asolid adsorbent by an adsorbing device and a desorbing device tocirculate the refrigerant between an evaporator and a condenser, so thatcold water is produced in an evaporator pipe provided in the evaporatorso as to penetrate therethrough. The refrigerator may be an absorptiontype refrigerator in which a refrigerant is circulated between acondenser and an evaporator by the use of an absorbing solution whichabsorbs refrigerant vapor, so that cold water is produced in anevaporator pipe provided in the evaporator so as to penetratetherethrough.

The gas extractor may be an ejector configured to draw in gas using aliquid flow. The gas extractor is allowed to extract the uncondensedgases from the refrigerator at a portion where the uncondensed gases aremost likely to accumulate. The condenser of the adsorption typerefrigerator may be subjected to the gas extraction, and the absorberdevice of the absorption type refrigerator may be subjected to the gasextraction, for example.

Preferably, the gas extraction tank includes a first liquid level gaugewhich outputs a water-level signal when a liquid level of therefrigerant in the gas extraction tank becomes the same as or lower thana predefined height;

the auxiliary tank includes a second liquid level gauge which outputs awater-level signal when a liquid level of the refrigerant in theauxiliary tank becomes the same as or higher than a predefined height;and

a controller of the gas extraction device is configured to perform a gasextraction operation by opening the shutoff valve, and continuouslyoperating the gas extraction pump until reception of the water-levelsignal output from the first liquid level gauge, and a filling operationby closing the shutoff valve, and continuously operating the gasextraction pump until reception of the water-level signal output fromthe second liquid level gauge.

In this case, the use of the first liquid level gauge enables propermanagement of a duration of the gas extraction performed by the gasextraction pump, and the use of the second liquid level gauge enablesproper discharge of the uncondensed gases from the gas extraction tankinto the auxiliary tank, and easy prevention of the refrigerant overflowfrom the auxiliary tank.

The duration of the gas extraction performed by the gas extraction pumpmay be set to a length of time suitably determined without using thefirst liquid level gauge.

Preferably, the circulation pipe includes a feed pipe connected to alower section of the evaporator and equipped with the gas extractionpump, and a return pipe connected to a lower section of the gasextraction tank and equipped with the shutoff valve; and

end portions of the feed pipe and the return pipe that are open to thegas extraction tank are positioned lower than the height of the liquidlevel of the refrigerant, which is established upon output of thewater-level signal from the first liquid level gauge.

This may prevent the uncondensed gases extracted into the gas extractiontank from accidentally flowing into the return pipe and being mixedtherein. This may further prevent the uncondensed gases extracted intothe gas extraction tank from accidentally flowing back into the feedpipe.

Preferably, a first tank valve is provided between the gas extractiontank and the auxiliary tank;

a second tank valve is provided above the auxiliary tank; and

the controller is configured to close the first tank valve whenperforming the gas extraction operation, open the first tank valve andthe second tank valve when performing the filling operation, and closethe first tank valve when receiving the water-level signal output fromthe second liquid level gauge.

In this case, upon the gas extraction, the first tank valve is closed soas to prevent outside air from being mixed into the gas extraction tankby way of the auxiliary tank. After the filling operation, the firsttank valve is closed so as to prevent the uncondensed gases, such as airand hydrogen, from being mixed into the gas extraction tank again by wayof the auxiliary tank.

Preferably, an upper section of the gas extraction tank has a shape witha horizontal sectional area that becomes smaller toward an upwarddirection; and

the auxiliary tank is connected to a portion at the upper section of thegas extraction tank, which has a minimum horizontal sectional area.

This may prevent a part of the uncondensed gases constituting a vaporphase component in the gas extraction tank from remaining in corners atthe upper section of the gas extraction tank when the refrigerant filledin the gas extraction tank overflows into the auxiliary tank. As aresult, all the uncondensed gases in the gas extraction tank are fullydischarged into the auxiliary tank.

EMBODIMENTS FOR CARRYING OUT THE INVENTION

Hereinafter, an embodiment of a gas extraction device for a refrigeratoris described in detail referring to the accompanied drawings.

As illustrated in FIGS. 1 to 3, a gas extraction device 5 for arefrigerator 1 according to the embodiment is installed in therefrigerator 1 that produces a cold water W by using heat of evaporationgenerated upon evaporation of a refrigerant A put in a vacuumizedevaporator 31.

The gas extraction device 5 is provided with a gas extraction tank 61, acirculation pipe 8, a gas extraction pump 71, a shutoff valve 72, a gasextractor 73, and an auxiliary tank 62.

The gas extraction tank 61 has a container shape and is used tocirculate the refrigerant A in the evaporator 31. The circulation pipe 8is connected to the gas extraction tank 61 and the evaporator 31 forcirculation therebetween. The gas extraction pump 71 is installed in thecirculation pipe 8 and used to feed the refrigerant A from theevaporator 31 to the gas extraction tank 61. The shutoff valve 72 isinstalled in the circulation pipe 8 and capable of blocking a flow ofthe refrigerant A from the gas extraction tank 61 to the evaporator 31.The gas extractor 73 extracts the uncondensed gases G in therefrigerator 1 into the gas extraction tank 61 using the refrigerant Asupplied from the evaporator 31 to the gas extraction tank 61. Theauxiliary tank 62 is connected to an upper section of the gas extractiontank 61 to cause the refrigerant A that is filled and overflows from thegas extraction tank 61 to inflow.

The gas extraction device 5 of the refrigerator 1 and a gas extractionmethod according to the embodiment will be hereinafter described indetail referring to FIGS. 1 to 7.

First, the refrigerator 1 according to the embodiment will be described.

FIGS. 4 and 5 are illustrations of the refrigerator 1. FIG. 5illustrates that an adsorbing device X1 and a desorbing device X2 of therefrigerator shown in FIG. 4 are switched.

As illustrated in these drawings, the refrigerator 1 according to theembodiment is an adsorption type refrigerator 1 in which vapor of therefrigerant A is repeatedly adsorbed to and desorbed from a solidadsorbent 211 by the adsorbing device X1 and the desorbing device X2 tocirculate the refrigerant A between an evaporator 31 and a condenser 32so that the cold water W is produced in an evaporator pipe 311 that isinserted into the evaporator 31.

The adsorption type refrigerator 1 has a plurality of (two in theembodiment) adsorbing/desorbing devices 2A and 2B each having a heattransfer pipe 21 inserted therethrough, a surface of which is appliedwith the solid adsorbent 211, the evaporator 31 configured tocommunicate with the plurality of adsorbing/desorbing devices 2A and 2Bindividually, and the condenser 32 configured to communicate with theplurality of adsorbing/desorbing devices 2A and 2B individually.

The adsorbing/desorbing devices 2A and 2B, the evaporator 31, and thecondenser 32 are configured to allow circulation of the refrigerant A(may be called refrigerant vapor A). The internal spaces of theadsorbing/desorbing devices 2A and 2B, the evaporator 31, and thecondenser 32 are vacuumized to allow easy evaporation of the refrigerantA. The evaporator 31 has an internal pressure equal to about 1/100 ofatmospheric pressure, and the condenser 32 has an internal pressureequal to about 1/20 of atmospheric pressure. According to theembodiment, the solid adsorbent 211 is silica gel, and the refrigerant Ais water.

There are communication paths 33 for the refrigerant vapor A to passthrough between the adsorbing/desorbing devices 2A and 2B, and theevaporator 31, and between the adsorbing/desorbing devices 2A and 2B,and the condenser 32. The communication paths 33 respectively havedampers 34 placed therein, which open and close the communication paths33 under their own weights and a pressure of the refrigerant vapor A.

As illustrated in FIGS. 4 and 5, the heat transfer pipes 21 of theadsorbing/desorbing devices 2A and 2B are installed up to the regionwhere two selector valve devices 46A and 46B are provided. The selectivevalve devices 46A and 46B switchably select between a cooling water Cand a warm water H to be circulated in the respective heat transferpipes 21.

The evaporator pipe 311 is inserted into the evaporator 31 as a passageof the cold water W. The evaporator pipe 311 is connected to a coldwater tank 44. The evaporator pipe 311 is connected to a refrigeratingdevice 45 to be cooled with supplied cold water W. The refrigeratingdevice 45 may be exemplified by an air conditioning system and arefrigerator, for example. The evaporator pipe 311 is arranged tocirculate through the evaporator 31, cold water tank 44, andrefrigerating device 45.

A condenser pipe 321 is inserted into the condenser 32 as a passage ofthe cooling water C. The condenser pipe 321 is connected to a coolingwater tank 41. The cooling water C from the cooling water tank 41 iscirculated to the condenser pipe 321 by way of the selector valve device46A, heat transfer pipes 21 of the adsorbing/desorbing devices 2A and2B, and the selector valve device 46B, and then returns to the coolingwater tank 41 from the condenser pipe 321.

The condenser 32 has a tray 35 for receiving the refrigerant A (water inthe embodiment) condensed and liquefied by the condenser pipe 321. Thereis a circulation pipe 36 between the tray 35 and the evaporator 31 tofeed the refrigerant A accumulated on the tray 35 to a surface of theevaporator pipe 311 in the evaporator 31.

The warm water H supplied to the heat transfer pipes 21 of theadsorbing/desorbing devices 2A and 2B is heated by exhaust heatdischarged from a heat generator 42 to generate heat. The heat generator42 may be exemplified by a solar energy assisted system, a gas enginesystem, a boiler, or a device configured to discharge vapor drain. Thewarm water H is obtained by the use of exhaust heat discharged from theheat generator 42 and stored in a warm water tank 43, and thencirculated to inlets of the heat transfer pipe 21 of theadsorbing/desorbing devices 2A and 2B via the selector valve device 46A.The warm water H is further circulated from outlets of the heat transferpipe 21 of the adsorbing/desorbing devices 2A and 2B to the heatgenerator 42 via the selector valve device 46B.

The cooling water C is water at 25° C. to 35° C. (about 30° C.), and thewarm water H is water heated to 70° C. to 90° C. (about 80° C.). Thecold water W in the evaporator pipe 311 in the evaporator 31 is cooleddown to 9 to 14° C. (about 11° C.).

The adsorption type refrigerator 1 is configured to be operated byswitching between the adsorbing/desorbing device 2A (or 2B) functioningas the adsorbing device X1 by circulating the cooling water C to theheat transfer pipe 21 and the adsorbing/desorbing device 2B (or 2A)functioning as the desorbing device X2 by circulating the warm water Hto the heat transfer pipe 21 at given time intervals to cool the coldwater W in the evaporator pipe 311 inserted into the evaporator 31. Theadsorption type refrigerator 1 continuously supplies the produced coldwater W from the cold water tank 44 to the refrigerating device 45.

The operation of the adsorption type refrigerator 1 will be hereinafterdescribed.

As illustrated in FIG. 4, the first adsorbing/desorbing device 2Afunctions as the adsorbing device X1 when the cooling water C issupplied to the heat transfer pipe 21 in the first adsorbing/desorbingdevice 2A. The solid adsorbent 211 applied to the surface of the heattransfer pipe 21 in the first adsorbing/desorbing device 2A is cooleddown, and the refrigerant vapor A is adsorbed to the solid adsorbent 211by adsorption reaction. Then, an internal pressure of the firstadsorbing/desorbing device 2A reduces to a lower pressure level than theinternal pressures of the evaporator 31 and the condenser 32. Affectedby the thus generated pressure difference, the damper 34 disposed in thecommunication path 33 between the first adsorbing/desorbing device 2Aand the evaporator 31 is opened, while the damper 34 disposed in thecommunication path 33 between the first adsorbing/desorbing device 2Aand the condenser 32 is closed. Then, the refrigerant vapor A in theevaporator 31 flows into the first adsorbing/desorbing device 2A andremoves heat of evaporation from the surface of the evaporator pipe 311in the evaporator 31, thus cooling down the cold water W in theevaporator pipe 311.

As illustrated in the drawing, when the cooling water C is supplied tothe heat transfer pipe 21 in the first adsorbing/desorbing device 2A,the warm water H is supplied to the heat transfer pipe 21 in the secondadsorbing/desorbing device 2B. The second adsorbing/desorbing device 2Bsupplied with the warm water H in the heat transfer pipe 21 functions asthe desorbing device X2. The solid adsorbent 211 applied to the surfaceof the heat transfer pipe 21 in the second adsorbing/desorbing device 2Bis heated, and the refrigerant vapor A is thus desorbed from the solidadsorbent 211 by desorption reaction. Then, an internal pressure of thesecond adsorbing/desorbing device 2B is elevated to a higher pressurelevel than the internal pressures of the evaporator 31 and the condenser32. Affected by the thus generated pressure difference, the damper 34disposed in the communication path 33 between the secondadsorbing/desorbing device 2B and the evaporator 31 is closed, while thedamper 34 disposed in the communication path 33 between the secondadsorbing/desorbing device 2B and the condenser 32 is opened. Then, therefrigerant vapor A in the second adsorbing/desorbing device 2B flowsinto the condenser 32, and the refrigerant vapor A is condensed by thecooling water C running in the condenser pipe 321 of the condenser 32.The condensed refrigerant vapor A is circulated into the evaporator 31through the circulation pipe 36.

When an amount of the refrigerant vapor A adsorbed to the solidadsorbent 211 in the first adsorbing/desorbing device 2A functioning asthe adsorbing device X1 is about to reach a saturation amount, the twoselector valve devices 46A and 46B are manipulated as illustrated inFIG. 5 to circulate the warm water H to the heat transfer pipe 21 in thefirst adsorbing/desorbing device 2A, and circulate the cooling water Cto the heat transfer pipe 21 in the second adsorbing/desorbing device2B. Then, the function of the first adsorbing/desorbing device 2A isswitched to the desorbing device X2, while switching the function of thesecond adsorbing/desorbing device 2B to the adsorbing device X1.Accordingly, the second adsorbing/desorbing device 2B functions as theadsorbing device X1, and the first adsorbing/desorbing device 2Afunctions as the desorbing device X2 as described above.

Thereafter, supply of the cooling water C and the warm water H to theheat transfer pipe 21 in the first adsorbing/desorbing device 2A and theheat transfer pipe 21 in the second adsorbing/desorbing device 2B isswitched in turn at given time intervals. Accordingly, twoadsorbing/desorbing devices 2A and 2B are switchably used as theadsorbing device X1 and the desorbing device X2 in turn at given timeintervals, so that the cold water W generated in the evaporator pipe 311is continuously supplied to the refrigerating device 45 via the coldwater tank 44.

Next, the gas extraction device 5 will be described.

FIGS. 1 to 3 illustrate a structure of the gas extraction device 5. FIG.1 is an illustration of the gas extraction device performing a gasextracting operation (gas extraction step). FIG. 2 is an illustration ofthe gas extraction device performing a filling operation (filling step).FIG. 3 is an illustration of the gas extraction device when operatingthe refrigerator 1. These drawings illustrate the evaporator 31 alone,while omitting any other devices of the refrigerator 1. A gas extractionpipe 322, which will be described later, is connected to inside of thecondenser 32 of the refrigerator 1. In these drawings, the currentlyactive pumps 314 and 71 and opened valves 611, 621, 72, 83, 84, and 86are illustrated in white. Meanwhile, currently inactive pumps 314 and71, and the closed valves 611, 621, 72, 83, 84, and 86 are illustratedin black.

As illustrated in FIG. 3, the liquefied refrigerant A is contained inthe evaporator 31. The evaporator 31 is provided with a refrigerantdrip-feed pipe 312 configured to drip the liquefied refrigerant A as aliquid phase component in a lower section, into a vapor phase in anupper section. An upper end portion of the refrigerant drip-feed pipe312 inserted in the evaporator 31 has a nozzle 313 through which therefrigerant A drips. A lower end portion of the refrigerant drip-feedpipe 312 has a drip-feed pump 314 which suctions the liquefiedrefrigerant A from the evaporator 31 and drips the suctioned liquefiedrefrigerant A through the nozzle 313. The drip-feed pump 314 remainsactive at all times so far as the refrigerator 1 which continuouslyproduces the cold water W is operating.

As illustrated in FIGS. 1 and 2, an upper section 613 of the gasextraction tank 61 according to the embodiment has a shape where ahorizontal sectional area is smaller toward upward direction. Morespecifically, the upper section 613 of the gas extraction tank 61 has adome shape so that the gas extraction tank 61 becomes the highest at ahorizontal center position. The upper section 613 of the gas extractiontank 61 is not necessarily limited to the dome shape but may be formedin a conical shape.

The auxiliary tank 62 is connected to a horizontal center of the uppersection 613 of the gas extraction tank 61 where the horizontal sectionalarea is reduced to minimum as the highest position.

The circulation pipe 8 includes a feed pipe 81 connected to a lowersection of the evaporator 31 and equipped with the gas extraction pump71, and a return pipe 87 connected to a lower section of the gasextraction tank 61 and equipped with the shutoff valve 72. The feed pipe81 according to the embodiment is bifurcated at a position downstream ofthe gas extraction pump 71 and then connected to the gas extraction tank61. More specifically, the feed pipe 81 is bifurcated at a positiondownstream of the gas extraction pump 71 into a gas extraction pipesection 82 connected to the gas extraction tank 61 via the gas extractor73 and a bypass pipe section 85 directly connected to the gas extractiontank 61 without passing through the gas extractor 73. The gas extractionpipe section 82 has switching valves 83 and 84 configured to open andclose at upstream and downstream sides of the gas extractor 73. Thebypass pipe section 85 has an opening-closing valve 86.

A first tank valve 611 configured to open and close is provided betweenthe gas extraction tank 61 and the auxiliary tank 62, and a second tankvalve 621 configured to open and close is provided above the auxiliarytank 62.

As illustrated in FIGS. 1 and 2, the gas extraction tank 61 is providedwith a first liquid level gauge 612 therein, which outputs a water-levelsignal when a liquid level of the refrigerant A in the gas extractiontank 61 is equal to or lower than a predefined height. The first liquidlevel gauge 612 detects an amount of the uncondensed gases G extractedinto the gas extraction tank 61 based on the height of the liquid levelof the refrigerant A. The first liquid level gauge 612 may be providedat a lower position in the gas extraction tank 61. Adjustment of theposition in height of the first liquid level gauge 612 allows the liquidlevel of the refrigerant in the gas extraction tank 61 and the amount ofthe uncondensed gases G to be extracted into the gas extraction tank 61to be suitably set.

The auxiliary tank 62 is provided with a second liquid level gauge 622therein, which outputs a water-level signal when the liquid level of therefrigerant A in the auxiliary tank 62 is equal to or higher than apredetermined height. The second liquid level gauge 622 detects anamount of the refrigerant A flowing into the auxiliary tank 62 based onthe height of the liquid level of the refrigerant A. The second liquidlevel gauge 622 may be provided at a longitudinally intermediateposition in the auxiliary tank 62. Adjustment of the position in heightof the second liquid level gauge 622 allows the amount of therefrigerant A flowing into the auxiliary tank 62 to be suitably set.

An end portion 821 of the gas extraction pipe section 82 and an endportion 871 of the return pipe 87 both open to the gas extraction tank61 are located lower than the height of the liquid-level of therefrigerant A, which are established upon output of the water-levelsignal from the first liquid level gauge 612. The aforementionedstructure prevents the uncondensed gases G extracted into the gasextraction tank 61 from accidentally flowing into the return pipe 87 andflowing back to the feed pipe 81. The gas extraction pipe section 82 isinserted into the gas extraction tank 61 from above and provided to aposition lower than the position of the first liquid level gauge 612.

As illustrated in FIGS. 1 and 2, the gas extractor 73 according to theembodiment corresponds to an ejector 73 configured to draw in gas usinga liquid flow. The ejector 73 has a gas draw-in passage formed on anouter or inner side of a liquid passage. The liquid passage is connectedto an intermediate position of the gas extraction pipe section 82, andthe gas draw-in passage is connected to the inside of the condenser 32of the refrigerator 1 via the gas extraction pipe 322.

The gas extraction pump 71 according to the embodiment has a higherdischarge pressure than atmospheric pressure (0.1 MPa) to cause therefrigerant A filled in the gas extraction tank 61 to overflow into theauxiliary tank 62 opened under atmospheric pressure.

The refrigerator 1 according to the embodiment is controlled by acontroller (control computer or control sequencer) to manipulate the twoselector valve devices 46A and 46B, drip-feed pump 314, gas extractionpump 71, shutoff valve 72, first tank valve 611, second tank valve 621,and switching valves 83, 84, and 86. The water-level signals output fromthe first liquid level gauge 612 and the second liquid level gauge 622are transmitted to the controller.

The controller according to the embodiment implements a gas extractingoperation in which the shutoff valve 72 is opened and the first tankvalve 611 and the second tank valve 621 are closed, and the gasextraction pump 71 is continuously operated until the water-level signaloutput from the first liquid level gauge 612 is received as illustratedin FIG. 1, and a filling operation in which the shutoff valve 72 isclosed and the first tank valve 611 and the second tank valve 621 areopened, and the gas extraction pump 71 is continuously operated untilthe water-level signal output from the second liquid level gauge 622 isreceived as illustrated in FIG. 2. When the controller receives thewater-level signal from the second liquid level gauge 622 during thefilling operation, the controller closes the first tank valve 611 andthe second tank valve 621.

A method for discharging the uncondensed gases G in the refrigerator 1using the gas extraction device 5 according to the embodiment will bedescribed referring to a flowchart illustrated in FIG. 6.

Prior to the discharge of the uncondensed gases G, the refrigerator 1 isoperated to produce the cold water W continuously in the evaporator pipe311 of the evaporator 31. As illustrated in FIG. 3, the drip-feed pump314 of the evaporator 31 is operated, while the gas extraction pump 71remains inactive. The shutoff valve 72, and the switching valves 83, 84,and 86 are closed.

After the refrigerator 1 is operated over a given period of time (forexample, a few days), the operation of the refrigerator 1 is stopped,and the gas extracting step is performed to extract the uncondensedgases G, such as air and hydrogen, accumulated in the refrigerator 1 asillustrated in FIG. 1. During the gas extracting operation, thedrip-feed pump 314 is kept active, while stopping the operation of therefrigerator 1. The gas extraction pump 71 is operated with the firsttank valve 611, second tank valve 621, and switching valve 86 of thebypass pipe section 85 are kept closed (Step S1 of FIG. 6, subsequentsteps will be recited with symbols alone). Then, the shutoff valve 72and the switching valves 83 and 84 of the gas extractor 73 are opened(S2).

The refrigerant A is circulated between the evaporator 31 and the gasextraction tank 61, and the uncondensed gases G in the condenser 32 aredrawn into the gas extraction tank 61 using the refrigerant A passingthrough the gas extractor 73 (S3). The gas extracting operationcontinues until the controller receives the water-level signal from thefirst liquid level gauge 612 (S4). More specifically, when theuncondensed gases G are extracted into the gas extraction tank 61, thevapor phase component in the gas extraction tank 61 increases.Meanwhile, the refrigerant A as the liquid phase component reduces, thuslowering the liquid level of the refrigerant A. When the liquid level ofthe refrigerant A in the gas extraction tank 61 is equal to thepredefined height, the first liquid level gauge 612 transmits thewater-level signal to the controller. Then, the controller switches thestep from the ongoing gas extracting operation to the filling operation.

In the filing step, the controller closes the shutoff valve 72 and theswitching valves 83 and 84 of the gas extractor 73, while opening thefirst tank valve 611, second tank valve 621, and switching valve 86 ofthe bypass pipe section 85 (S5) to continue the operation of the gasextraction pump 71 as illustrated in FIG. 2.

The refrigerant A circulated from the evaporator 31 by the gasextraction pump 71 is continuously accumulated in the gas extractiontank 61. When the gas extraction tank 61 is filled up with therefrigerant A, the refrigerant A starts overflowing into the auxiliarytank 62 (S6). Then, the uncondensed gases G and outside air constitutingthe vapor phase component in the gas extraction tank 61 are forced outby the refrigerant A into the auxiliary tank 62 and then discharged fromthe auxiliary tank 62 into atmosphere.

Since the auxiliary tank 62 is released to atmosphere, the refrigerant Ain the auxiliary tank 62 drops into the gas extraction tank 61. Theuncondensed gases G and outside air are mixed both in the gas extractiontank 61 and the auxiliary tank 62.

When the liquid level of the refrigerant A in the auxiliary tank 62reaches the predetermined height, the second liquid level gauge 622 inthe auxiliary tank 62 transmits the water-level signal to the controller(S7). The controller then closes the first tank valve 611 and the secondtank valve 621 (S8) and stops the operation of the gas extraction pump71 (S9). In this way, the gas extraction device 5 successfullydischarges the uncondensed gases G in the refrigerator 1 intoatmosphere.

As illustrated in FIG. 3, the switching valves 83, 84, and 86 are closedand the drip-feed pump 314 is operated while having the gas extractionpump 71 inactive to restart the operation of the refrigerator 1. Afterthe refrigerator 1 is operated over a given period of time (for example,a few days), the uncondensed gases G are similarly extracted while therefrigerator 1 is stopped.

The gas extraction tank 61 that contains the uncondensed gases G has aninternal pressure higher than that of the evaporator 31. Under theresultant pressure difference therebetween, the refrigerant A thatresides in the return pipe 87 is circulated into the evaporator 31.

According to the gas extraction device 5 of the refrigerator 1 and thegas extraction method in the embodiment, the refrigerant A in theevaporator 31 is supplied to the gas extraction tank 61 by the gasextraction pump 71 and the gas extractor 73 so as to extract theuncondensed gases G in the refrigerator 1 into the gas extraction tank61 using the combination of the gas extraction pump 71 and the gasextractor 73. After the uncondensed gases G are extracted into the gasextraction tank 61, the gas extraction pump 71 is continuously operatedby closing the shutoff valve 72. The refrigerant A discharged into thegas extraction tank 61 by the gas extraction pump 71 fills up the gasextraction tank 61 and starts overflowing into the auxiliary tank 62.

In this way, the gas extraction device 5 successfully discharges all theuncondensed gases G extracted into the gas extraction tank 61, such asair and hydrogen, into the auxiliary tank 62 and then discharges theuncondensed gases G from the auxiliary tank 62 into atmosphere.

This makes it possible to prevent the uncondensed gases G from residingin the gas extraction tank 61. Therefore, it is unnecessary toadditionally provide a device, such as a water ejector and a vacuumpump, to discharge the uncondensed gases G remaining in the vacuumizedgas extraction tank 61 (at an internal pressure lower than atmosphericpressure) into atmosphere. Further, the gas extraction tank 61 is filledup with the refrigerant A to prevent the uncondensed gasses G fromremaining in the gas extraction tank 61. This may prevent backflow ofthe uncondensed gases G and outside air into the refrigerator 1 whenextracting the uncondensed gases G are extracted by the gas extractionpump 71 and the gas extractor 73.

The gas extraction device 5 of the refrigerator 1 and the gas extractionmethod according to the embodiment may prevent the uncondensed gases G,such as air and hydrogen, from remaining in the gas extraction tank 61and further prevent the uncondensed gases G and outside air from flowingback into the refrigerator 1.

The gas extraction pump 71 and the drip-feed pump 314 according to theembodiment are connected in parallel to the evaporator 31, andseparately operated. As illustrated in FIG. 7, a drip-feed pump 314A anda gas extraction pump 71A are connected in series to the evaporator 31,the refrigerant drip-feed pipe 312 is connected to the nozzle 313 fromthe portion between the drip-feed pump 314A and the gas extraction pump71A, and the refrigerant drip-feed pipe 312 is equipped with a switchingvalve 315. In this case, the switching valve 315 provided in therefrigerant drip-feed pipe 312 is opened to selectively operate thedrip-feed pump 314 alone during the operation of the refrigerator 1.

To extract the uncondensed gases G, the switching valve 315 of therefrigerant drip-feed pipe 312 is closed, and the drip-feed pump 314Aand the gas extraction pump 71A are both operated. Therefore, therefrigerant A in the evaporator 31 is discharged into the gas extractiontank 61 by two pumps, that is, the drip-feed pump 314A and the gasextraction pump 71A. In the case where the gas extraction pump 71A has adischarge pressure equal to or lower than atmospheric pressure (0.1MPa), a sum of the discharge pressure of the gas extraction pump 71A andthe discharge pressure of the drip-feed pump 314A may be made higherthan the atmospheric pressure.

Though not illustrated in the drawings, the refrigerator 1 is notnecessarily limited to the adsorption type refrigerator 1 but may be anabsorption type refrigerator in which an absorbing solution whichabsorbs the refrigerant vapor A (lithium bromide solution) is used tocirculate the refrigerant A between the condenser 32 and the evaporator31, so that cold water is produced in the evaporator pipe inserted intothe evaporator 31. The absorption type refrigerator uses an absorberdevice containing the absorbing solution which absorbs the refrigerantvapor A evaporated from the evaporator 31 and a regenerator device whichreceives the absorbing solution including the refrigerant A from theabsorber device and separates the refrigerant A from the absorbingsolution by heating. The refrigerant vapor A in the regenerator deviceflows into the condenser 32. The refrigerant vapor A is cooled down inthe condenser 32 and then drops into the evaporator 31 to be used as therefrigerant A in the evaporator 31.

In the absorption type refrigerator, a similar gas extraction device 5can be installed to work with the evaporator 31. The gas draw-in passageof the gas extractor (ejector) 73 may be connected to the absorberdevice where the uncondensed gases G are most likely to accumulate. Thestructure of the gas extraction device 5 of the absorption typerefrigerator is similar to that of the gas extraction device of theadsorption type refrigerator 1 and provides a similar operationaleffect.

1. A gas extraction device for a refrigerator, which is installed in therefrigerator configured to produce cold water using heat of evaporationgenerated when evaporating a refrigerant put in a vacuumized evaporator,the gas extraction device for removing an uncondensed gas that exists inthe refrigerator comprising: a gas extraction tank for circulating therefrigerant in the evaporator; a circulation pipe for circulationbetween the gas extraction tank and the evaporator; a gas extractionpump installed in the circulation pipe to feed the refrigerant in theevaporator to the gas extraction tank; a shutoff valve installed in thecirculation pipe so as to shut off a flow of the refrigerant from thegas extraction tank to the evaporator; a gas extractor for extractingthe uncondensed gas in the refrigerator into the gas extraction tankusing the refrigerant supplied from the evaporator to the gas extractiontank; and an auxiliary tank connected to an upper section of the gasextraction tank and receives an inflow of the refrigerant filling up thegas extraction tank, and overflowing therefrom.
 2. The gas extractiondevice for a refrigerator according to claim 1, wherein: the gasextraction tank includes a first liquid level gauge which outputs awater-level signal when a liquid level of the refrigerant in the gasextraction tank becomes the same as or lower than a predefined height;the auxiliary tank includes a second liquid level gauge which outputs awater-level signal when a liquid level of the refrigerant in theauxiliary tank becomes the same as or higher than a predefined height;and a controller is provided, which is configured to perform a gasextraction operation by opening the shutoff valve, and continuouslyoperating the gas extraction pump until reception of the water-levelsignal output from the first liquid level gauge, and a filling operationby closing the shutoff valve, and continuously operating the gasextraction pump until reception of the water-level signal output fromthe second liquid level gauge.
 3. The gas extraction device for arefrigerator according to claim 2, wherein: the circulation pipeincludes a feed pipe connected to a lower section of the evaporator andequipped with the gas extraction pump, and a return pipe connected to alower section of the gas extraction tank and equipped with the shutoffvalve; and end portions of the feed pipe and the return pipe that areopen to the gas extraction tank are positioned lower than the height ofthe liquid level of the refrigerant, which is established upon output ofthe water-level signal from the first liquid level gauge.
 4. The gasextraction device for a refrigerator according to claim 2, wherein: afirst tank valve is provided between the gas extraction tank and theauxiliary tank; a second tank valve is provided above the auxiliarytank; and the controller is configured to close the first tank valvewhen performing the gas extraction operation, open the first tank valveand the second tank valve when performing the filling operation, andclose the first tank valve when receiving the water-level signal outputfrom the second liquid level gauge.
 5. The gas extraction device for arefrigerator according to claim 1, wherein: an upper section of the gasextraction tank has a shape with a horizontal sectional area thatbecomes smaller toward an upward direction; and the auxiliary tank isconnected to a portion at the upper section of the gas extraction tank,which has a minimum horizontal sectional area.
 6. A gas extractionmethod for a refrigerator, which uses the gas extraction device for arefrigerator according to claim 1, the method comprising: gas extractionstep of opening the shutoff valve accompanied with an operation of thegas extraction pump, circulating the refrigerant in the evaporator tothe gas extraction tank, and drawing the uncondensed gas in therefrigerator into the gas extraction tank using the gas extractor; anddischarging step of closing the shutoff valve accompanied with theoperation of the gas extraction pump, filling up the gas extraction tankwith the refrigerant put in the evaporator so as to be overflowed intothe auxiliary tank, and discharging the uncondensed gases drawn andstored in the gas extraction tank into the auxiliary tank.
 7. The gasextraction device for a refrigerator according to claim 3, wherein: afirst tank valve is provided between the gas extraction tank and theauxiliary tank; a second tank valve is provided above the auxiliarytank; and the controller is configured to close the first tank valvewhen performing the gas extraction operation, open the first tank valveand the second tank valve when performing the filling operation, andclose the first tank valve when receiving the water-level signal outputfrom the second liquid level gauge.
 8. The gas extraction device for arefrigerator according to claim 2, wherein: an upper section of the gasextraction tank has a shape with a horizontal sectional area thatbecomes smaller toward an upward direction; and the auxiliary tank isconnected to a portion at the upper section of the gas extraction tank,which has a minimum horizontal sectional area.
 9. The gas extractiondevice for a refrigerator according to claim 3, wherein: an uppersection of the gas extraction tank has a shape with a horizontalsectional area that becomes smaller toward an upward direction; and theauxiliary tank is connected to a portion at the upper section of the gasextraction tank, which has a minimum horizontal sectional area.
 10. Thegas extraction device for a refrigerator according to claim 4, wherein:an upper section of the gas extraction tank has a shape with ahorizontal sectional area that becomes smaller toward an upwarddirection; and the auxiliary tank is connected to a portion at the uppersection of the gas extraction tank, which has a minimum horizontalsectional area.
 11. A gas extraction method for a refrigerator, whichuses the gas extraction device for a refrigerator according to claim 2,the method comprising: gas extraction step of opening the shutoff valveaccompanied with an operation of the gas extraction pump, circulatingthe refrigerant in the evaporator to the gas extraction tank, anddrawing the uncondensed gas in the refrigerator into the gas extractiontank using the gas extractor; and discharging step of closing theshutoff valve accompanied with the operation of the gas extraction pump,filling up the gas extraction tank with the refrigerant put in theevaporator so as to be overflowed into the auxiliary tank, anddischarging the uncondensed gases drawn and stored in the gas extractiontank into the auxiliary tank.
 12. A gas extraction method for arefrigerator, which uses the gas extraction device for a refrigeratoraccording to claim 3, the method comprising: gas extraction step ofopening the shutoff valve accompanied with an operation of the gasextraction pump, circulating the refrigerant in the evaporator to thegas extraction tank, and drawing the uncondensed gas in the refrigeratorinto the gas extraction tank using the gas extractor; and dischargingstep of closing the shutoff valve accompanied with the operation of thegas extraction pump, filling up the gas extraction tank with therefrigerant put in the evaporator so as to be overflowed into theauxiliary tank, and discharging the uncondensed gases drawn and storedin the gas extraction tank into the auxiliary tank.
 13. A gas extractionmethod for a refrigerator, which uses the gas extraction device for arefrigerator according to claim 4, the method comprising: gas extractionstep of opening the shutoff valve accompanied with an operation of thegas extraction pump, circulating the refrigerant in the evaporator tothe gas extraction tank, and drawing the uncondensed gas in therefrigerator into the gas extraction tank using the gas extractor; anddischarging step of closing the shutoff valve accompanied with theoperation of the gas extraction pump, filling up the gas extraction tankwith the refrigerant put in the evaporator so as to be overflowed intothe auxiliary tank, and discharging the uncondensed gases drawn andstored in the gas extraction tank into the auxiliary tank.
 14. A gasextraction method for a refrigerator, which uses the gas extractiondevice for a refrigerator according to claim 5, the method comprising:gas extraction step of opening the shutoff valve accompanied with anoperation of the gas extraction pump, circulating the refrigerant in theevaporator to the gas extraction tank, and drawing the uncondensed gasin the refrigerator into the gas extraction tank using the gasextractor; and discharging step of closing the shutoff valve accompaniedwith the operation of the gas extraction pump, filling up the gasextraction tank with the refrigerant put in the evaporator so as to beoverflowed into the auxiliary tank, and discharging the uncondensedgases drawn and stored in the gas extraction tank into the auxiliarytank.